Masking is a common method of protecting a surface from receiving paint when paint is being applied to an adjacent or nearby surface. For instance, when painting window frames, it is undesirable to get paint on the glass of a window. It is well known to apply masking tape to the glass before painting the window frames to protect the glass from paint. It is also common to make a cut-out of paper sized to fit over the glass and use tape to secure the edges to the glass. After painting, the masking tape and/or paper are removed and disposed of, leaving the glass underneath free of paint. Although the materials used are inexpensive and adaptable to any surface size or shape, this method of masking suffers from being very labor intensive.
To address this problem, several reusable masks have been developed which require less labor. U.S. Pat. No. 2,286,473, for example, shows an apron for covering the lower half of an automobile body while the top half is being painted. The apron is attached at the top to the automobile body by a rubber strip containing a passage connected to a vacuum pump. The rubber strip also contains numerous ports spaced periodically in the passage which vent the partial vacuum in the passage to the surface of the auto body to secure the apron to the auto body. The top of the apron forms the sharp division between the area to be painted and the area protected from paint. The apron also has suction cups attached to its bottom which are used to fix the bottom of the apron to the lower parts of the auto body, preventing the apron from flapping during paint application.
U.S. Pat. No. 2,371,859 also shows an apron for masking the lower half of an automobile body while the top half is being painted. In this case, the fabric apron is also attached at the top to the automobile body by a rubber strip containing a row of large suction pockets. The large suction pockets are provided to secure the strip of rubber to the automobile body and to support the weight of the apron. One or more rows of smaller suction pockets are provided at the edges of the rubber strip to adjust and perfect the placement of the strip's edges. Each pocket must form an individual seal with the automobile body, so application of the strip requires pressing the surface of the strip over each pocket.
U.S. Pat. No. 4,406,246 shows a rigid paint mask for covering a window. This mask is guided into position by contact with the molding around the window, and held in place by a suction cup mounted underneath each comer of the mask. These suction cups attach to the glass of the window.
U.S. Pat. No. 4,915,058 also shows a rigid paint mask for covering an automobile window. This mask has a suction cup at each end to attach the mask to the glass and is sized slightly smaller that the window. Because of the mask's size, it still requires the application of masking tape to mask the edges of the window and the molding surrounding the window.
Conventional paint masks, such as the ones described above, continue to have disadvantages. A primary drawback is that these masks are only cost-effective if very large numbers of identical items are being painted. This is due partially to the specificity of the mask, with each mask being manufactured for one particular size and shape of window, and partially to the relative expense of making these masks, all of which require either difficult custom manufacturing or the assembly of several parts.